The conventional navigation apparatus has a built-in smart electronic map and can execute functions of route planning and navigation. The user is only required to input a name or a coordinate of a destination to be leave for, or directly select a particular location on the electronic map, and then the navigation apparatus plans a navigation route based on the detected location and a geographical location of the destination input by the user, and delivers a voice message to guide the user to the destination along the planned navigation route.
However, in order to provide users with detailed map information, ordinary electronic map is usually mixed with complex contents. Besides basic marks such as line map, road name of each road, all points of interest (POI) in the frame such as gas station, convenience store, restaurant and viewpoint, and building, if further accompanied with function icons and keys such as compass, scale, volume, start and end point setting, 2D/3D switch, the whole screen is almost filled up. Accordingly, when performing the navigation function in practice, the navigation route always mixes up with those marks icons, and keys, which effects the user's judgments on the navigation route. As a result, the user may look at wrong marks or get lost in the route with slight carelessness, which results in circumstances such as driving to a wrong lane or missing the timing for making a turn.